Digital laser dynamic caustics experiment method and system thereof

Abstract

The invention discloses a digital laser dynamic caustics experiment method and a system thereof. The system comprises a laser device, a beam expanding mirror, a field lens assembly, an uploading device, a synchronous control switch, a digital high speed camera and a computer. A continuous line beam is emitted by the laser device, converted into plane beam through the beam expanding mirror, converted into parallel beams through the field lens to shoot on the surface of a test piece and finally converged to be conveyed in a camera lens of the digital high speed camera. With starting of the uploading device, the digital high speed camera is synchronously controlled to be started to finish dynamic record of crack expanding processes on the test piece, namely, digital dynamic caustics record is finished. The system can be used for optical measurement mechanics analysis in dynamic broken experiment processes like impact, explosion and the like and is simple in light path system, convenient to operates, low in experiment cost, short in period and capable of continuously detecting the whole broken processes and improving experiment accuracy.

Description

technical field [0001] The invention relates to a dynamic optical measurement mechanics experiment method, in particular to a digital laser dynamic caustic line experiment method for studying crack tip singularity and stress concentration degree and a system for realizing the method. Background technique [0002] In the research on fracture problems at home and abroad, optical fracture mechanics is the preferred experimental method in the study of dynamic fracture, which mainly includes dynamic photoelasticity, dynamic caustics, moiré and moiré interferometry, CGS (coherent gradient sensing method) and other experimental methods. In addition to the caustics test method, other experimental methods have encountered many specific difficulties except for the stress singularity problem at the crack tip caused by the sharp change of stress in the vicinity of the crack tip. In the caustic experiment method, the characteristic length of the caustic spot provides a quantitative meas...

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Problems solved by technology

However, because the experimental system needs delay controllers, photoelectric devices, etc. to control and check the discharge time of sparks, the effect of photography is not easy to control; and the film used is traditional optical and physical film, which requires stricter operating requirements for experimenters. ; these lead to a low success rate of the experiment

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